This invention relates to telecommunications and, more particularly, to a telecommunication monitoring system which monitors both fixed and mobile systems.
The rapid pace of innovations and technological advances within the telecommunication industry has severely challenged the law enforcement community ability to conduct authorized electronic surveillance in order to monitor criminal activity over telecommunication resources. Resources such as wireless telephones, cellular telephones, wideband wireless telephones, packet data networks that send voices and/or messages over multiple routes over a network having multiple paths, all make monitoring very difficult. In 1994 the Communications Assistance for Law Enforcement Act, hereinafter referred to as CALEA, was enacted to require carriers to assist authorized surveillance.
CALEA requires telecommunications carriers to ensure that the carriers' equipment, facilities, and services are able to comply with authorized electronic surveillance orders. At least since Jun. 30, 2000, a known and used surveillance system that complies with CALEA is the passive monitoring of voice paths system shown in FIGS. 1 and 2.
FIG. 1 shows a system 100 of equipment for use by authorized personnel to monitor a call from a calling party to a called party. The system 100 has a station 104, which is used by the calling party who often is a crime suspect. Calling station 104 is connected to the public switched telephone network (PSTN) 108. Calling station 104 is shown as a typical fixed telephone connected by a wire 106 to PSTN 108, but station 104 could also be a wireless station, an Internet net-to-telephone station or a pay telephone depending on the character of the suspected activity of the calling party. For example, a member of organized crime might have the calling station 104 at his or her home, the location of which does not help law enforcement in fighting organized crime since such locations are already known. On the other hand, if a kidnapper is using station 104 he or she would want to keep his or her location and identity secret since finding a kidnapper often leads to finding the kidnapper's victim. So when a criminal suspect wants his or her, location a secret, he or she can use a pay telephone and keep the session short to keep law enforcement from determining the pay telephone location. Another way for a criminal suspect can keep his or her location and identity secret is to use stolen wireless telephones and keeps the session short since wireless telephone location techniques are easier and faster than pay telephones. It is worth noting that no matter what kind of telephone the criminal suspect uses, calling station 104 is connected to the PSTN 108.
PSTN 108 is connected by means of telecommunications switch 110 in one way or another to the called party station 114. Most times the location of the called party station 114 and the identity of the called party are known to monitoring the party. Typically the called party knows the called party station 114 is being monitored, but in some cases the called party does not know that. As before in the case of organized crime, the called party at the called station 114 might not know he or she is being monitored, but in organized crime cases, the called party might expect one or both ends of conversation to be monitored. Because monitoring is expected, the called party might take precautions such as use a wireless telephone of the cellular or wideband handheld communication device, and move around in order to make possible monitoring attempts difficult. For such cases, it is important to monitor mobile called party telephones.
The more challenging situation for monitoring personnel is not an uncommon one. This situation occurs when the called party is a victim of criminal activity. In such a situation, the called party at station 114 knows about and agrees to monitoring by a law enforcement party at monitoring station 116. For existing monitoring arrangements, most often the law enforcement party is located nearby. Monitoring, as shown in FIGS. 1 and 2, is provided by the switch 110. The switch 110 is connected to both the called station 114 and the monitoring station 116. The bridge 111 in FIGS. 1 & 2 is part of the switch 110. The connections between the switch 110 and the stations 114 and 116 are by means of the all encompassing PSTN 108. The specific connection between station 114 and station 116 is by a bridge 111, which can be part of switch 110, or it can alternatively be an adjunct unit to switch 110.
FIG. 2 shows a simplified operation of the known monitoring system 100. The typical monitoring situation, as shown by the first row of FIG. 2, has calling station 104, usually operated by a criminal; called station 114, usually operated by a victim or co-criminal; and monitoring station 116 monitored by law enforcement personnel. As shown by the second row of FIG. 2, calling station 104 is lifted off-hook and calls the called station 114. The call causes called station 114 to ring according to typical operation. Atypically, except for CALEA or similar monitoring, bridge 111 also sends a separate ring signal to monitoring station 116 to alert the monitoring personnel of the incoming call without providing a ring-back signal to either the calling station 104 or the called station 114. As shown by the third row of FIG. 2, station 116 going off-hook to “answer” the call does not affect the ringing of station 114 or the ring back tone heard at calling station 104, but it does stop the ringing at station 116. At this point, station 116 has a “passive” connection to calling station 104, so the ring back tone of station 114 can be heard over this passive connection, as shown in the third row of FIG. 2. If station 114 goes off-hook to answer the incoming call, a “normal” connection will be connected between station 104 and station 114. At the same time, bridge 111 will maintain the passive connection to station 116 so both sides of the call can be heard by monitoring personnel, but spoken words and/or background noises at station 116 are isolated from station 114 and station 104.
In normal monitoring situations, called party at station 114 is located nearby to station 116. The nearby location of monitoring station 116 is an expediency since in the known monitoring system 100 the monitoring station 116 is for listening-only, communication between law enforcement personnel and the called party is by whispers, notes or gestures, all of which must be located nearby. All because monitoring station 116 does not have an outbound voice path that accepts voice or other sound inputs from monitoring personnel to the called party. Such whispers, signs and gestures are stressful to the called party when he or she is on a two-way conversation with the calling party and at the same time trying to understand what the monitoring personnel want the called party to say to the calling party. Additionally, with the popularity of hand-held and car-mounted wireless telephones, the called station 114 could be in a car or in a park, so wireless telephones may mean whispers, signs and gestures would be very difficult and very impractical to provide by the monitoring personnel. Without the close proximity and communication of the called party with the law enforcement, monitoring personnel; critical instructions and encouragements to the called party (often a victim) are not available in the known system 100.